Abstract
This paper reports the results of an empirical investigation of some methods for improving the quality of precipitation probability forecasts. These methods include 1) techniques for adjusting subjective and objective forecasts using past reliability data and 2) techniques for combining these two types of forecasts via both averaging and a more sophisticated statistical aggregation procedure. The empirical results indicate that forecast performance can be improved through such methods, with the greatest improvements arising from averaging forecasts that have previously been adjusted.
